Grass Growing In Rock Beds

Last summer I cleared out all the grass around the entire perimeter of my house and patio and put in rock beds. I put down the black landscape fabric under the rocks and black tubular edging between the yard and the rocks.

Unfortunately I wasn't careful enough last fall when I put down grass seed and I must have planted a decent amount of seed in the rocks. Somehow it seems to grow better in there than it does in the yard! So my problem is that it's a very large area and I keep seeing more and more grass in the rocks as well as some weeds. It's all above the landscape fabric so I can easily pull them out but it's just a big area and I'll clear an area out and then see more stuff there a week later.

Does anyone know of a product that I could just spray on all of the rocks to kill everything without harming the grass that's right on the other side of the edging or any of the plants in the rock beds? We only put plants in the front and back of the house last year so my fiance is going to want to plant stuff on the sides this year and this solution needs to avoid killing those as well.

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Grass Growing In Rock Beds

Roundup will work fine. Just be careful how you spray it so it doesn't get on the grass. You can also cover the plants in the rock bed you are afraid of hitting with a plastic bag to keep the stuff off them.

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Grass Growing In Rock Beds

My suggestion is to use a non-selective herbicide such as Roundup (glyphosate) or one of the generic brands of glyphosate along with a pre-emergent herbicide. Most garden centers carry Preen. Pre-em's need to be watered in with 1/2 to 1 inch of water.

One method would be to apply the pre-emergent and water in, then apply the glyphosate. You just don't want to wash off any contact herbicide that you apply. Most of the labels direct the application "when weeds are actively growing" and/or "do not apply to plants under stress such as drought" which is why my practice is to irrigate with fertilizer a day or so beforehand then apply the herbicide. If I am also applying a pre-emergent, I apply it and immediately water it in, wait a day or two then apply the Roundup. Be patient, glyphosate takes several days to work. I don't expect a good kill in much less than a week.